A method is provided for automatically applying named styles to existing documents including word processing documents. The existing document is scanned and parsed into style regions of uniform style. The style attributes of each uniform style region are identified, and these identified style attributes are used to create style groups containing style regions having identical or substantially identical style attributes. These style attributes can be expressed in set or vector form. Named styles are then associated with the identified style group by either comparing the style attributes of a given style group to the attributes of a pre-defined named style or by extracting a named style from the style group. Once associated with a named style, the style regions within a given style group can be modified to be consistent with the named style associated with the style group. In addition, subsequent changes to the style attributes in a given style region are made by changing the attributes of the named style associated with the style group containing that style region.